This invention relates to a door guard for locking a door in a predetermined half-open position (i.e., one of the positions between fully open and fully closed positions).
One example of this type of a door guard is disclosed in Japanese Utility Model Publication Hei 4-54286. This door guard comprises a retaining member fixed to a body, a pivotal lever whose basal end portion is pivotably supported by the door, and a position restricting means for restraining the pivotal lever in a lock position and in a release position with a predetermined amount of force exerted by a first biasing means. In a release position, the pivotal lever allows the door to swing freely but in a lock position, when the door is swung from a dosed position to a predetermined half-open position, the pivotal lever is pivoted by a second biasing means so as to be engaged with a retaining member. By this, the door is locked in the predetermined half-open position.
The conventional door guard includes a first biasing means for maintaining the pivotal lever in the lock position or in the release position, and a second biasing means for pivoting the pivotal lever so as to be engaged with the retaining member when the door is swung to the predetermined half-open position. If those two biasing means can be replaced by only one biasing means, parts can be reduced in number and therefore, the manufacturing costs can be reduced to that extent.
The subject matter of the present invention resides in a door guard comprising:
a retaining member fixed to a body;
a pivotal lever whose basal end portion is pivotably supported by a door;
position restricting means including biasing means, the position restricting means restraining the pivotal lever in a lock position and in a release position with a predetermined amount of force exerted by the biasing means, the biasing means biasing the pivotal lever such that the pivotal lever returns to the lock position within a range of a predetermined return angle from the lock position;
forced pivoting means, when the door is swung from the closed position to the open position in a state in which the pivotal lever is pivoted to the lock position, the forced pivoting means pivoting the pivotal lever within a range of the return angle from the lock position against the biasing force of the biasing means as the door is swung open and when the door reaches the half-open position, the forced pivoting means allowing the pivotal lever to pivot to the lock position side by the biasing force of the biasing means; and
the retaining member being formed with an engagement portion, when the pivotal lever, which has been pivoted from the lock position by the forced pivoting means, is pivoted to the lock position side by the biasing means, the engagement portion being brought into engagement with the pivotal lever to prevent the pivotal lever from moving in a swinging direction of the door.
It is preferred that the position restricting means includes the biasing means and a pivot pin pivotably supported by the door and nonpivotably disposed on the basal end portion of the pivotal lever, thereby pivotably connecting the pivotal lever to the door; and
the pivot pin having a first and a second position restricting portion which are formed on an outer peripheral surface thereof in such a manner as to be away from each other in a circumferential direction of the pivot pin; and
the biasing means restraining the pivotal lever in the lock position by being abutted with the first position restricting portion under the effect of its own biasing force and restraining the pivotal lever in the release position by being abutted with the second position restricting portion.
It is also preferred that two of the first and second position restricting means are provided, the two first restricting means are arranged about 180 degrees away from each other in a circumferential direction of the pivot pin and the two second restricting means are likewise arranged about 180 degrees away from each other in the circumferential direction of the pivot pin, and the first and second position restricting means are alternately arranged in the circumferential direction of the pivot pin.
It is also preferred that the forced pivoting means includes a forced pivoting portion disposed on the retaining member, when the door is swung open from a closed position in a state in which the pivotal lever is pivoted in the lock position, the forced pivoting portion being brought into contact with the pivotal lever to thereby pivot the pivotal lever out of the lock position.
It is also preferred that in a neutral position where the lever is away by the return angle from the lock position to the release position side, the position restricting means restrains the pivotal lever in the neutral position, when the pivotal lever is pivoted from the neutral position to the lock position, the biasing means biases the pivotal lever to the lock position side and when the pivotal lever is pivoted from the neutral position to the release position side, the biasing means biases the pivotal lever to the release position side, and the pivotal lever is provided with an abutment portion which is abutted with the retaining member when the door is swung open from the closed position in a state in which the pivotal lever is pivoted to the neutral position.
It is also preferred that the abutment portion projects towards the retaining member side.
It is also preferred that the position restricting means restrains the pivotal lever in a stable position between the neutral position and the release position by a biasing force of a predetermined value of the biasing means.